<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="../vue.js"></script>
    <style>
      .bg_a{
        background-color: red;
      }
      .bg_b{
        background-color: blue;
      }
      .fs{
        font-size: 50px;
      }
      .fc{
        color: chartreuse;
      }
    </style>
  </head>
  <body>
    <div id="app">
      <div :class="bg" @click="change">{{name}}</div>
      <div :class="obj" >{{name}}</div>
      <div :class="list" >{{name}}</div>
    </div>
    <script>
      Vue.config.productionTip = false;
      new Vue({
        el:'#app',
        data:{
          name:'ANSWER',
          bg:"bg_a",
          obj:{bg_b:true,fs:true},
          list:['bf_a','fc'],
        },
        methods:{
          // change(){
          //   this.bg ="bg_b";
          // }
        }
      });
    </script>
  </body>
</html>
